Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.

User Name:

Password

Please enter a password for your user account. Note that passwords are case-sensitive.

Password:

Confirm Password:

Email Address

Please enter a valid email address for yourself.

Email Address:

Log-in

User Name

Remember Me?

Password

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Additional Options

Miscellaneous Options

Automatically parse links in text

Automatically embed media (requires automatic parsing of links in text to be on).

Automatically retrieve titles from external links

Topic Review (Newest First)

07-30-2012 09:00 PM

39 chev

I have been running GMC 6-71 and 4-71 blowers on stock small blocks for about 35 years,and have never had a problem.I have used them on 327,350 and 400 small blocks,all with stock dampers and cranks. I am currently driving a 39 chevy coupe with a 6-71 blown 350.I rebuilt the engine in my home garage using all stock parts. I am also building a T-bucket,this one is powered with a stock Targetmaster 350 using a 4-71 blower driven at crank speed.I am running the 6-71 underdriven for street driving. I am 65 years old,and I see you are 17 if you plan on thrashing that engine(Racing etc) you will definately need forged pistons and a steel crank.

07-30-2012 04:35 PM

against all odds

But more importantly, i would like to apologize to jesumi for using the "w" term; This was completely inappropriate----for an adult, like me, to use a term like that with you--a child. Even though i'm pretty sure you know what it means.

Please accept my apology and i'd like to ask for everyone else's understanding as well. This was wrong. Let us substitute the phrase "blowing smoke" instead.

So, with that out of the way, i think it's really important to establish a budget for this (and any) project. It does no good to start and then run out of money. Also, i don't think it's wise to spend everything you got on an engine. i think 20% is reasonable.

07-30-2012 04:30 PM

against all odds

i think it's somewhere in between 400 and 500hp, so i said 400 to be safe. And as far as cracking i think it will start in the base of the cylinder wall, but i would have to double check. But i really believe that stock blocks really can't handle more than 400 to 500hp. Not for very long at least. i would welcome any comments criticizing or augmenting my statements.

07-29-2012 03:09 PM

vinniekq2

Is it 400 or 500 horse power? and where does it crack? You have me worried now.

07-29-2012 10:22 AM

against all odds

i'm afraid stock blocks can't take much over 500hp on a regular basis without cracking.

07-28-2012 09:39 PM

vinniekq2

against all odds,what happens to a stock block if I exceed 400HP?

07-28-2012 09:33 PM

against all odds

Actually, before we go any further it would be best to establish the budget for the engine.

Anything otherwise is just wanking.

07-28-2012 01:11 PM

against all odds

In my opinion a stock block can't take more than say 400hp on a regular basis so you don't need to worry about a "supercharger friendly cam;" A stock cam will do just fine for 400hp.

1) Will a centrifugal supercharger put strain on the crank nose---i don't know; Small block chevy crank noses CANNOT take the strain of a roots type blower. (not sure about the smaller ones though---144, 177's etc.)

This needs to be researched first and foremost.

If you want to go roots and are happy with around 400hp/450tq then i would at the very least be looking at a forged crank with a larger nose----such as what scat offers. Personally, if i was going to go all that way, i would also be looking at a hi-po block such as bowite or dart; This way i can just crank to boost up to get 500, 600, 700 etc. ponies.

07-27-2012 01:48 PM

327NUT

Get "the book" and read it!! most of your questions will be answered........

07-27-2012 12:22 PM

jeseusmi

thanks for the advise. id like to make this car for the drag strip but i still wanna be able to drive it on the road so im not sure what size blower i should get. and if i do get a bigger like the 6-71 what would i need to have changed?

07-27-2012 09:08 AM

XNTRCI-T

Hey Grant, I'm not a moron! I did my "get this book" on the thread he posted on the Engines board before the threads were combined.

Hey jeseusmi, Grant (GT23T) and I are both blown T-bucket guys. We strongly recommend you educate yourself with that book so that you can ask the right questions when you are ready to build your motor.

how much power do you need? If its for looks and not a serious race car you can under drive the blower with a near stock cam and make 400 plus reliable hp,very cheap.There are a couple cars like that in my neighbourhood,2 of them have been running over 10 years with nothing other than normal services.one rat rod is raced a few times every year.It runs low 12,s with 2 carter AFBs.Obviously the car makes 400 HO or less